Brooks Glycerin Max 2 vs Brooks Glycerin Flex:
Which to Choose

The clearest gap is stack and weight. The Glycerin Max 2 sits on a towering 45 mm heel / 37 mm forefoot platform and tips the scale at 318 g (men's US 9), while the Glycerin Flex rides a much lower 35 mm heel / 26 mm forefoot stack at about 264 g — roughly 54 grams lighter and over a centimeter closer to the ground. That difference defines everything else. The Max 2 delivers genuinely maximum cushioning (6/6 to the Flex's 4/6), with a deep, pillowy heel, a slightly firmer forefoot, and a GlideRoll rocker that gently tips you forward so cruising feels effortless — but the tall, heavy platform can feel a touch tippy in quick direction changes and starts fighting you as the pace climbs. The Flex takes the opposite approach: instead of a rocker, it uses deep flex grooves that let the shoe bend with your foot for a smoother, more natural transition, giving it a nimbler, more connected feel at the cost of some plushness and heel protection. Both use the same dual-cell DNA Tuned foam and both are firmly damped rather than springy — responsiveness is modest on each (4/6 vs 3/6), so neither offers race-foam pop. Stability is neutral on both, with the Max 2 rating slightly higher (4/6 vs 3/6) thanks to its wide base, though that edge is tempered by its very tall stack. Drop is effectively a wash: 8 mm measured on the Max 2 versus about 9 mm on the Flex, both moderate ramps (and both marketed by Brooks at 6 mm). Their optimal pace windows also overlap heavily in easy, steady-effort territory, with each going vague once you push much past roughly 5:30 min/km. Up top, the Max 2 uses a triple jacquard air mesh while the Flex wears an engineered flat-knit — both breathable, accommodating daily-trainer uppers.